#include <stdio.h>
int f(int a)
{
	if (a == 1) { return 1; }
	else 
	{ 
		int n;
		int product = 1;
		for (n = a; n > 1; n --)
		{ product = n * product; }
		return product; 
	}
}

int main(int argc, char * argv[])
{
	printf("f(6) = %d\n", f(6));
	return 0;
}
